V401 Series weir type diaphragm valves are widely used especially in chemical process lines containing particles and do not cause jamming in the internal structure of the particles passing through the line as in other valves. Diaphragm valves provide excellent process control in the control of particulate fluids, especially in chemically corrosive environments. Fully elastomer or PTFE coated diaphragm valves are widely used in excessively chemically corrosive process lines, not affected by sediments (weir type body valves).